1. Technical Field
The present invention relates to a method for determining the pose of a camera relative to a real environment and to a method for recognizing an object of a real environment in an image taken by a camera. Furthermore, the invention relates to a method for providing a data model that is intended to be compared with data of an image taken by a camera in a method for determining the pose of a camera relative to a real object of a real environment or in a method for recognizing an object of a real environment.
2. Background Information
Augmented Reality (AR) is a technology in which virtual data are overlaid with reality and which thus facilitates the association of data with reality. The use of e.g. mobile AR systems is already known in the prior art. In the past years, high-performance mobile devices (e.g. so-called smartphones) turned out to be suitable for AR application. These devices meanwhile have comparatively large color displays, installed cameras, good processors and additional sensors, such as e.g. orientation sensors and GPS. In addition thereto, the position of the device can be approximated via radio networks. In the past, there were various projects implemented on mobile devices using AR. At first, there were used special optical marks for ascertaining the position and orientation of the device. In more recent times, there are also approaches to utilize GPS and the orientation sensor systems of more modem devices. (AR Wikitude. http://www.mobilizy.com/wikitude.php.; S. Feiner, B. Macintyre, T. Hollerer, and A. Webster. A touring machine: Prototyping 3d mobile augmented reality systems for exploring the urban environment. In Proceedings of the 1st International Symposium on Wearable Computers, pages 74-81, 1997; Sekai Camera. http://www.tonchidot.com/product-info.html; Marko Heinrich, Bruce H. Thomas, Stefan Mueller, “AR Weather,” Mixed and Augmented Reality, IEEE/ACM International Symposium on, pp. 187-188, 2008 7th IEEE/ACM International Symposium on Mixed and Augmented Reality, 2008; layar.com).
However, it is noticeable in this regard that the registration, i.e. the accuracy of overlaying is worthy of improvement due to unsafe sensor data. An approach to this end is the use of hybrid tracking that improves initial poses of the camera from the combination of e.g. GPS, compass and gravitation sensors by optical approaches. Often, so-called “histogram equalization” of the image data is employed in order to reduce the susceptibility to varying light conditions.
Object recognition of a real object in an image taken by a camera and initialization of optical tracking systems for determining the camera pose relative to a real environment are known in the prior art. However, the reliability of the systems may occasionally vary greatly with varying environmental conditions. The camera pose in this regard is the position and orientation of the camera in space. The reality may be present e.g. in any form as data model, for example as 3D model describing the geometric properties of the reality or part of the reality.
The publication US 2003/0025714 describes a system visualizing weather data by means of augmented reality. The publication US 2005/0231419 A1 describes an AR system that monitors the airspace by means of weather-independent sensors and displays airspace information by means of AR.